Computers are complex systems made up of numerous components, e.g. executable software and hardware components for executing the software. Executable software components include operating systems, device drivers, and software applications. Protocols specify how two or more components communicate. Because of the multitude of hardware and software component designs and manufacturers, many components are incompatible. For example, the majority of software applications are specific to a particular operating system and are not executable by another operating system. Even if the underlying source code is generalized sufficiently to be compiled for different operating systems, the resulting software application cannot be transferred from one operating system to another without requiring a compilation of the source code for the new operating system.
Designers of executable software for a specific operating system must bear this situation in mind when designing and writing executable software applications. One approach is to create software applications for execution by a single particular operating system, such as WINDOWS 2000 available from Microsoft Corp, on a particular hardware system. The combination of operating system and computer hardware is referred to as a platform. In this approach, the software application will not be portable to other operating systems, for example, operating system-specific software applications designed for execution by a WINDOWS 2000 operating system is not executable by a MACINTOSH operating system available from Apple Computer, Inc., and vice versa.
Another approach is to design software applications to utilize an intermediate executable software component, i.e., an intermediate operating environment, providing an interface between the software application and the operating system. The most common example of an intermediate component is a virtual machine, for example a JAVA virtual machine (JAVA VM or JVM). JAVA is available from Sun Microsystems. While a JAVA VM must be tailor-written specific to an operating system, JAVA language-based software applications are executable by any JAVA VM irrespective of the underlying operating system. The disadvantage of this approach is that the software application is dependent on the JVM to interface with the operating system and can not access functionality not provided by the JVM. For example, the JVM may not provide a JAVA-based software application access to certain low-level networking capabilities provided by the operating system, which would be accessible to software applications written for a specific operating system.
It is known in the art to generate unique identifiers (UID), also referred to as global unique identifiers (GUID) and universal unique identifiers (UUID), using executable software to obtain unique data stored on a computer system. However, prior approaches to generating a UID of which the inventor is aware require the use of platform-specific information to generate a UID.
Most computer systems include an ethernet interface card for enabling network access from the computer system to a network. Because of an agreed to licensing system between ethernet card manufacturers, each ethernet card includes a unique media access control (MAC) address as part of the ethernet card hardware. Because the MAC address is defined to be unique between ethernet cards, most frequently the MAC address, or a generated MAC address, e.g., a pseudo-MAC address, is used as the basis for the UID. At a minimum, existing UID generation mechanisms use the MAC address as an input in combination with other parameters.
One difficulty with using platform-specific information to generate a UID is that in order to access such platform-specific information the UID generation mechanism must be aware of the platform-specific information and include a method to access the information for each platform on which the UID is to be generated. UID generation software developed for one platform, e.g., a personal computer executing Microsoft Windows operating system, will not be able to operate on another platform, e.g., a personal computer executing HP-UX operating system, as described above.
Executable software written for one platform, i.e., a particular processor and operating system capability, is not transferable to another platform, e.g., Microsoft Windows-based executables will not execute on an HP-UX Unix operating system.
One solution to this problem is the use of an intermediate operating environment such as Sun Microsystems' JAVA Virtual Machine (JVM) and the corresponding JAVA programming language. Under this approach, an intermediate operating environment is written for execution on a particular platform. Because the programming interface to the intermediate operating environment is standard across platforms, software written for an intermediate operating environment on one given platform is executable without change on the same intermediate operating environment of a different platform. The JVM is one such intermediate operating environment and the JAVA programming language provides the common programming interface for software developed for the JVM. Through the use of the JVM and the JAVA programming language, software may be written one time on one platform and thereafter be executable without change on other platforms having a JVM.
JAVA is a programming language designed to enable generation of software applications capable of executing on all platforms without modification. JAVA was originally developed in 1991 by Sun Microsystems, Inc. as a language for embedded applications. JAVA is an interpreted language wherein the source code is compiled into an intermediate language called bytecode. The bytecode is converted or interpreted into machine code at runtime. Thus, JAVA programs are not dependent on any specific hardware and run in any computer having a JAVA virtual machine.
Hardware Overview
FIG. 1 is a block diagram illustrating an exemplary computer system 100. The block diagram of computer system 100 is also applicable to mini-mainframes, servers, handhelds and the like.
Computer 100 includes a bus 102 or other communication mechanism for communicating information, and a processor 104 coupled with the bus 102 for processing information. Computer 100 also includes a main memory 106, such as a random access memory (RAM) or other dynamic storage device, coupled to the bus 102 for storing instructions to be executed by processor 104. Main memory 106 also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 104. Computer 100 further includes a read only memory (ROM) 108 or other static storage device coupled to the bus 102 for storing static information and instructions for the processor 104. A storage device 110, such as a hard disk drive, is provided and coupled to the bus 102 for storing instructions, temporary variables, and other intermediate information.
Computer 100 may be coupled via the bus 102 to a display 112, such as a flat panel display, for displaying an interface to a user. An input device 114, such as a keyboard including alphanumeric and function keys, is coupled to the bus 102 for communicating information and command selections to the processor 104. Another type of user input device is cursor control 116, such as a stylus, pen, mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor 104 and for controlling cursor movement on the display 112. This input device typically has two degrees of freedom in two axes, a first axis (e.g., x) and a second axis (e.g., y) allowing the device to specify positions in a plane.
Sequences of instructions may be read into main memory 106 from another computer-readable medium, such as storage device 110; however, the computer-readable medium is not limited to devices such as storage device 110. For example, the computer-readable medium may include a floppy disk, a flexible disk, hard disk, magnetic tape, or any other magnetic medium, a compact disc-read only memory (CD-ROM), any other optical medium, a random access memory (RAM), a programmable read only memory (PROM), an erasable PROM (EPROM), a Flash-EPROM, any other memory chip or cartridge, or any other medium from which a computer can read. Execution of the sequences of instructions contained in the main memory 106 causes the processor 104 to perform process steps. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with computer software instructions.
Computer 100 also includes a communication interface 118 coupled to the bus 102 and providing two-way data communication as is known in the art. For example, communication interface 118 may be an integrated services digital network (ISDN) card, a digital subscriber line (DSL) card, or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, communication interface 118 may be a local area network (LAN) card to provide a data communication connection to a compatible LAN. Wireless links may also be implemented. In any such implementation, communication interface 118 sends and receives electrical, electromagnetic or optical signals which carry digital data streams representing various types of information. For example, two or more computers 100 may be networked together in a conventional manner with each using the communication interface 118.
Network link 120 typically provides data communication through one or more networks to other data devices. For example, network link 120 may provide a connection through local network 122 to a host computer 124 or to data equipment operated by an Internet Service Provider (ISP) 126. ISP 126 in turn provides data communication services through the world wide packet data communication network now commonly referred to as the “Internet” 128. Local network 122 and Internet 128 both use electrical, electromagnetic or optical signals which carry digital data streams. The signals through the various networks and the signals on network link 110 and through communication interface 118, which carry the digital data to and from computer 100, are exemplary forms of carrier waves transporting the information.
Computer 100 can send messages and receive data, including program code, through the network(s), network link 120 and communication interface 118. In the Internet example, a server 130 might transmit a requested code for an application program through Internet 128, ISP 126, local network 122 and communication interface 118.
The received code may be executed by processor 104 as it is received, and/or stored in storage device 110, or other non-volatile storage for later execution. In this manner, computer 100 may obtain application code in the form of a carrier wave.
FIG. 2 is a high level block diagram depicting a layered view of a computer system hardware and software architecture 200. The architecture 200 includes computer hardware 100 (described in conjunction with FIG. 1 above), and an operating system 202, stored in ROM 108, main memory 106, or storage device 110. The processor 104 executes operating system 202 instructions from memory 106, ROM 108, or storage device 110. Instructions for a platform-specific executable 204, as is known in the art, are executed by the processor 104 and access functionality provided by the operating system 202. For example, the platform-specific executable 204 may be a word processor, a web browser, a spreadsheet program, an email program, or other software executables. Platform-specific executable 204 is also referred to as a native program. An example operating system 202 is HP-UX available from Hewlett-Packard Development Company, LLP.
An intermediate operating environment, i.e., a virtual machine 206, instructions are executed by processor 104 and cause the processor to access functionality provided by the operating system 202, e.g., function calls or method invocations. Virtual machine 206 executes a non-platform-specific (NPS) executable 208, i.e., a non-native program, for example a JAVA-based program, instructions to provide additional functionality on computer 100. As described above, an example virtual machine 206 is the JAVA virtual machine available from Sun Microsystems, Inc.
According to an embodiment of the present invention, the virtual machine 206 is the only component of the software architecture which must be customized for each specific hardware 100 and operating system 202 combination. That is, it is not necessary to customize the NPS executable 208 for a particular processor, graphics interface device, or other computer hardware or for a particular operating system 202 version or manufacturer. In contrast, each platform, i.e., operating system 202 and hardware 100 combination, requires a different version of the platform-specific executable 204.
The NPS executable 208 communicates via standard virtual machine language methods known to those skilled in the art. Having been designed according to the software architecture of the present invention, the NPS executable 208 is fully portable to another computer having a virtual machine 206, and an operating system 200. Each of the above components are typically standard on any computing device intended for direct human interaction, including desktops, laptops, servers, and handheld or embedded devices. The NPS executable 208 will execute on such a system regardless of the particular type of any of the abovementioned components.